Optical switch

Abstract

In an optical switch for connecting optically a first optical fiber supported on a stationary supporting block to a second optical fiber supported on a movable supporting block being movable relative to the stationary supporting block between a first position for the optical connection between the terminating ends of the first and second optical fibers and a second position for disconnecting the optical connection therebetween and being adjacent to the stationary supporting block, and a magnetic flux generator for generating a magnetic flux for moving the movable supporting block relative to the stationary supporting block, the movable supporting block includes a soft magnetic substance so that the magnetic flux passes through the movable supporting block.

What is claimed is:  
     
       1. An optical switch for connecting optically at least one first optical fiber to at least one second optical fiber selectively, comprising, 
       a stationary supporting block for supporting thereon a terminating end of the first optical fiber,  
       a movable supporting block for supporting thereon a terminating end of the second optical fiber, being movable relative to the stationary supporting block between a first position for the optical connection between the terminating ends of the first and second optical fibers and a second position for disconnecting the optical connection therebetween, and being adjacent to the stationary supporting block, and  
       a magnetic flux generator for generating a magnetic flux for moving the movable supporting block relative to the stationary supporting block,  
       wherein the movable supporting block includes a soft magnetic substance so that the magnetic flux passes through the movable supporting block.  
     
     
       2. An optical switch according to claim  1 , wherein the soft magnetic substance is a soft magnetic ceramic. 
     
     
       3. An optical switch according to claim  1 , wherein a thermal expansion coefficient of the stationary supporting block is substantially equal to that of the movable supporting block. 
     
     
       4. An optical switch according to claim  1 , wherein the stationary supporting block includes at least one of a ceramic and a glass so that a difference in thermal expansion coefficient between the stationary supporting block and the first optical fiber is kept small. 
     
     
       5. An optical switch according to claim  1 , wherein the movable supporting block includes at least one of a ceramic and a glass so that a difference in thermal expansion coefficient between the movable supporting block and the second optical fiber is kept small. 
     
     
       6. An optical switch according to claim  1 , further comprising a permanent magnet for generating another magnetic flux sufficient for maintaining the movable supporting block at a selected one of the first and second positions when the magnetic flux generator is prevented from generating the magnetic flux. 
     
     
       7. An optical switch according to claim  6 , wherein the another magnetic flux passes through the stationary supporting block. 
     
     
       8. An optical switch according to claim  7 , wherein the another magnetic flux passes through both of the stationary supporting block and the movable supporting block. 
     
     
       9. An optical switch according to claim  1 , wherein the magnetic flux generated by the magnetic flux generator passes through both of the stationary supporting block and the movable supporting block. 
     
     
       10. An optical switch according to claim  1 , wherein the stationary supporting block includes at least one of a soft magnetic substance and a ferromagnetic substance so that the magnetic flux passes through the stationary supporting block. 
     
     
       11. An optical switch according to claim  1 , wherein the stationary supporting block and the movable supporting block includes a common soft magnetic substance. 
     
     
       12. An optical switch according to claim  6 , wherein the magnetic flux generator includes a first magnetic flux generator and a second magnetic flux generator, a direction of the magnetic flux generated by the first magnetic flux generator is opposite to a direction of the magnetic flux generated by the permanent magnet in a magnetic circuit including the movable supporting block, the first magnetic flux generator and the permanent magnet while a direction of the magnetic flux generated by the second magnetic flux generator is equal to the a direction of the magnetic flux generated by the permanent magnet in a magnetic circuit including the movable supporting block, the second magnetic flux generator and the permanent magnet, so that the movable supporting block moves from the first position to the second position, and the direction of the magnetic flux generated by the first magnetic flux generator is equal to the direction of the magnetic flux generated by the permanent magnet in the magnetic circuit including the movable supporting block, the first magnetic flux generator and the permanent magnet while the direction of the magnetic flux generated by the second magnetic flux generator is opposite to the direction of the magnetic flux generated by the permanent magnet in the magnetic circuit including the movable supporting block, the second magnetic flux generator and the permanent magnet, so that the movable supporting block moves from the second position to the first position. 
     
     
       13. An optical switch according to claim  6 , further comprising a magnetically permeable member connected magnetically to the permanent magnet and including front portions facing to respective sides of the movable supporting block and being opposite to each other. 
     
     
       14. An optical switch according to claim  6 , wherein the permanent magnet is arranged between the stationary supporting block and the magnetic flux generator in a magnetic flux proceeding direction. 
     
     
       15. An optical switch according to claim  6 , wherein the stationary supporting block is arranged between the movable supporting block and the permanent magnet in a magnetic flux proceeding direction. 
     
     
       16. An optical switch according to claim  1 , wherein the soft magnetic substance is an oxide ferrite. 
     
     
       17. An optical switch according to claim  16 , wherein the oxide ferrite includes iron, manganese and zinc. 
     
     
       18. An optical switch according to claim  1 , wherein the soft magnetic substance is a single crystalline ferrite. 
     
     
       19. An optical switch according to claim  1 , wherein the stationary supporting block includes a ceramic having at least one of soft-magnetism and ferromagnetism. 
     
     
       20. An optical switch according to claim  1 , further comprising at least one guide pin contacting the stationary supporting block and the movable supporting block to guide a mutual movement of the stationary supporting block and the movable supporting block between the first and second positions, and the guide pin is prevented from having a magnetic permeability. 
     
     
       21. An optical switch according to claim  1 , wherein a distance between the stationary supporting block of at least one of soft-magnetism and ferromagnetism and the movable supporting block of soft-magnetism is kept substantially constant so that a magnetic gap between the stationary supporting block and the movable supporting block is kept substantially constant. 
     
     
       22. An optical switch according to claim  6 , wherein the magnetic flux generator includes first and second magnetic flux generators connected electrically in series, and a direction of the magnetic flux through the permanent magnet generated by the first magnetic flux generator in a magnetic circuit including the first magnetic flux generator, the permanent magnet, the stationary supporting block and the movable supporting block is opposite to a direction of the magnetic flux through the permanent magnet generated by the second magnetic flux generator in a magnetic circuit including the second magnetic flux generator, the permanent magnet, the stationary supporting block and the movable supporting block.